The LEDs should be fine as long as the heatsink is good enough and the current is within the rating.
In the image linked, the LEDs are connected in series and can't easily be controlled individually, as the power supply is constant current, you should short circuit the LEDs you don't want to be on but it isn't the ideal way of doing it.
they dont have to be wired in a series thats just how that person made their fixture im going to use it for my coral reef fish tank and i wanted to simulate sunrise sunset and moon light
i was saying that he wired them in a series but i don't necessarily have to do it that way that was just one example
i want to be able to control the ammount of blue and white light seperatly and also only have a few blue and white on at night and have them fade in automatically and out every day
In your case, I think its pointless access LEDs separately. You better buy two High Power LED drivers with dimming option and balance the color and brightness.
that is not true the lights need to be on full for about 8 hours and then only a couple of them stay on called moonlights to imitate the light the moon produces on the reefs at night hence the name moonlights and what i was trying to do was create a controller so i didn't need a timer
Seriously it could be a fake but I've seem some pretty amazing octopus videos so it's definitely plausible.
EDIT:
Maybe it had to do with the bright lights being on in the night when the octopus expects and wants it to be dark? I know that would annoy me and it seemed to upset the little octopus, otherwise it wouldn't have turned them off.